Premier 21.1.0 Horizontal Timeline zoom shortcuts no longer working

Hiya - This has been discussed elsewhere, but would categorise as an urgent request. 
On Macs (Ours are M1 Sonoma) the Horizontal timeline zoom keyboard shortcut no longer works. 

It's really slowing down our editors - one workaround is highlighting the Project window and then the Timeline horiz zoom shortcuts work again but that's not a fix.
 
I hear that windows10 users may not have this issue in 24.1.0